Malicious Backdoor Discovered in GitHub PoC: Cybersecurity researchers have found a proof-of-concept (PoC) on GitHub that conceals a backdoor using a deceptive persistence method. The PoC, disguised as a harmless learning tool, silently executes a Linux bash script while masquerading as a kernel-level process.
Initially posing as a PoC for a high-severity flaw in the Linux kernel, the repository was eventually taken down after being forked multiple times.
The backdoor embedded in the PoC possesses the ability to steal sensitive data from compromised systems and grant remote access to threat actors by adding their SSH key to the .ssh/authorized_keys file. Disguised within the Makefile, the PoC instructs users to run a make command, which compiles and builds executables.
However, the code snippet within the Makefile builds and executes malware, specifically a file named “kworker” that establishes persistence by modifying the .bashrc file.
This discovery comes shortly after the identification of fake GitHub accounts distributing malware through deceptive PoC exploits for popular software. Users who have downloaded and executed these PoCs are advised to revoke unauthorized SSH keys, delete the kworker file, remove the kworker path from the bashrc file, and inspect the /tmp/.iCE-unix.pid directory for potential threats.
While distinguishing legitimate PoCs from deceptive ones can be challenging, adopting secure practices such as testing in isolated environments, such as virtual machines, can provide an additional layer of protection.